1. Technical Field
Embodiments of the invention include an image processing device, a color conversion table creating device, a display device, an image processing method, a color conversion table creating method, and a method of manufacturing the display device that color-converts a color value in any color space into a color value in other color space.
2. Related Art
In the past, color matching was widely conducted for assimilating the difference of a color area between a color reproduction space reproducible by a display device such as a projector or a display and a color space (hereinafter, referred to as “target color space”) of a display target such as sRGB and achieving a color reproduction in accordance with the target color space by the display device.
As an example of the color matching, if a color value is matched in the overlapped area of the target color space and the color reproduction space by one to one, the color reproduction suitable for the target color space call be carried out. In addition, in order to effectively utilize the high luminance area of the color reproduction spaces the color reproduction may be carried out so as to take advantage of the entire area of the color reproduction space including the high luminance area by matching the color value on the color reproduction space outside the target color space with the color value inside the target color space with respect to the outside of the overlapped area of the target color space and the color reproduction space (for example, see JP-A-2003-18415).
Furthermore, in the technique described in JP-A-2003-18415, the color conversion is carried out under the assumption that a tone characteristic for each primary color of RGBs in the display device before the color conversion is a fixed tone characteristic, for example, γ=2.2. The color conversion is performed in a color space of a curved gray axis space that comes close to the gray axis of the color reproduction space from the gray axis of the target color space as the brightness increases, it may achieve the color reproduction having the color characteristic that comes entirely close to the target color space while utilizing effectively the high luminance area of the color reproduction space.
However, according to JP-A2003-18415, since the tone characteristic assumed in the first color conversion unit and the tone characteristic adjusted actually in the second color conversion unit are different to each other, the accuracy may be deteriorated.
For example, in the case where the gray axis or the like of the display device before the color conversion is properly corrected in advance and the tone characteristic for each primary color is different to that is assumed at the color conversion, the adjustment accuracy of the gray characteristic deteriorates.
As described above, according to the related art, there was a problem that an accurate adjustment of the gray characteristic is difficult at the matching of the color area.